Drive shaft?

Hi everyone, we have been enjoying our 06 Bee for almost a year and a half now. Lately she has developed a shake (shimmy if you will) that has gotten worst. Yesterday my mechanic told me the bad news, both her left and right drive shafts needed to be replaced at a cost of about CAN$3500!! I tried calling to source them aftermarket but seems only MB has them, besides of course junk shops. She has 190,000KM (got her at 115,000Kms) and we do around 200Kms a day up and down Hwy 400 north of Toronto. My mechanic tells me that is a lot of money for the car, considering its age and mileage and would consider another car at this point. Appreciate any thoughts from you loyal Bee owners out there as I ponder our next move.